05000272/LER-2007-001

LER-2007-001, ESF Actuation of Auxiliary Feedwater Pumps in Mode 3.

Docket Number
Event date:	03-27-2007
Report date:	05-23-2007
Reporting criterion:	10 CFR 50.73(a)(2)(iv)(B), System Actuation
2722007001R00 - NRC Website

PLANT AND SYSTEM IDENTIFICATION

Westinghouse — Pressurized Water Reactor (PWR/4) Auxiliary Feedwater System (AFW) {BM* Engineered Safety Features Actuation System {JE/} * Energy Industry Identification System {EIIS} codes and component function identifier codes appear as {SS/CCC}

IDENTIFICATION OF OCCURRENCE

Event Date: March 27, 2007 Discovery Date: March 27, 2007

CONDITIONS PRIOR TO OCCURRENCE

Salem Unit 1 was in Operational Mode 3 at 0% reactor power, entering the 18th Refueling Outage.

No structures, systems or components were inoperable at the time of the discovery that contributed to the event.

DESCRIPTION OF OCCURRENCE

On March 27, 2007, an Engineered Safeguards Feature (ESF) {JE/} actuation occurred during the beginning of refueling outage 1R18 following the transition from the Emergency Operating procedures (EOP) to the Integrated Operating Procedures (10P). At the time of the event, the operators were establishing the initial conditions for an Auxiliary Feedwater (AFW) {BM pump full flow test. The Steam Generator (S/G) levels were being maintained at 25% in preparation for the full flow test. The 25% S/G level was selected to accommodate the full flow from the AFW pump and the subsequent increase in S/G levels. Maintaining S/G levels at 25% with the 13 AFW pump was assigned to the plant operator (PO).

A delay occurred in performing the AFW, during which time the Reactor Coolant system (RCS) cooldown was commenced via steam dumps. The PO placed a demand signal to start opening steam dump valve 13TB10 but the valve opened later than expected. S/G levels were still being maintained at 25% at this point. Steam demand was raised to raise the cooldown rate. No adjustment to AFW flow was performed, because the PO believed he had a rising trend in S/G level. This apparent rising trend was initially due to the swell in level when the steam demand was raised. However, actual S/G levels steadily lowered over the next few minutes.

�NRC FORM 366 (6-20041 PRINTFO ON RFCYCI Fll PAPFR DESCRIPTION OF OCCURRENCE (Contd) During this time the extra CRS was trying to resolve the test equipment issues associated with the full flow AFW test. When the lower levels were observed, the PO raised AFW flow and notified the CRS and the extra SRO that S/G levels were outside the established control parameter of 25%. The extra CRS observed S/G levels and ordered the PO to minimize S/G blow down, however it was too late to prevent the ESF actuation that occurred at 2050. The 13 S/G reached the 14% ESF actuation set point and S/G blow down automatically isolated. The CRS then ordered the cooldown stopped and steam dumps were closed. The 11 and 12 S/G levels also dropped below the 14% set point. The lowest level during this transient occurred in 13 Steam Generator and was 11.3% narrow range level. The operators raised AFW flow to all S/Gs, and the S/G levels were restored to greater than 14% at 2054.

This event is reportable in accordance with 10CFR50.73 (a)(2)(iv)(A), "any event or condition that resulted in manual or automatic actuation of any of the systems listed in paragraph (a)(2)(iv)(B) of this section.

PREVIOUS OCCURRENCES

A review of LERs at Salem Station dating back to 2002 identified three previous events where AFW system ESF actuations had occurred as result of low Steam Generator level.

1. 272/02-005-00 - Unexpected Auto Start of 13 AFP at Start of 1R15 was due to ineffective implementation of the Design Change Package (DCP) for the SIG low-low level setpoint change; 2. 272/02-004-00 - Manual Reactor Trip and Automatic Auxiliary Feedwater Actuation on Low Steam Generator Level Due to Feedwater Pump Runback was the result of a design issue; 3. 311/06-005-00 - Automatic Start of Auxiliary Feedwater Pumps in Mode 4 was due to a lack of broad oversight and coordination of all control room activities occurring simultaneously.

The cause of the first two events was design change process related and the corrective actions associated with these events would not have prevented this event. The cause of the last event was the lack of broad command and control of multiple control room activities; the corrective actions associated with this event were focused at providing lessons-learned briefings reinforcing expectations of those in command and control during multiple activities. These briefings were performed prior to 1R18 and contributed to an enhanced overall understanding of all activities in the control room. These corrective actions would not have prevented this event.

CAUSE OF OCCURRENCE

The causes of the event were the failure of the operating crew to establish clear termination criteria for stopping the cooldown based on low S/G levels, and the lack of clear guidance for maintaining S/G levels, especially termination criteria, during a cooldown in the Hot Standby to Cold Shutdown integrated operating procedure.

• NRC FORM 366A(1-2001

SAFETY CONSEQUENCES AND IMPLICATIONS

There was no actual safety consequences associated with this event; sufficient cooling was always maintained. The low level in the 11, 12 and 13 S/G occurred as a result of human error and was not caused by equipment malfunction. The safety systems responded to the low S/G level as designed.

A review of this event determined that a Safety System Functional Failure (SSFF) as defined in NEI 99- 02, Regulatory Assessment Performance Indicator Guidelines, did not occur. There was no condition that alone could have prevented the fulfillment of a safety function of a system needed to remove residual heat.

CORRECTIVE ACTIONS

1.PInitiated a prompt investigation of event, and subsequent root cause evaluation.

2. Personnel involved with this event have been held accountable in accordance with PSEG policies.

3. Operations conducted 'stand downs' to reemphasize the application of Operations fundamentals, particularly Control Board awareness and Teamwork.

4.PPrior to Mode ascension at the end of 1R18, the following actions were taken:

a. Crew composition adjustments made, b. Repaired steam dump valve 13TB10, c. Additional oversight was assigned during critical evolutions, requiring Operations Manager presence at pre-job briefs to reinforce expectations, and d. Just-In-Time (JIT) Training on AFW control at low power.

5.PProcedure IOP-6, Hot Standby to Cold Shutdown, will be revised to include a level band on all S/Gs prior to initiating cooldown and establishing cooldown termination criteria with respect to minimum S/G levels.

6.PAdditional corrective actions include:

a. Reinforcement of operating and human performance fundamentals.

b. An extent of condition review to identify other procedures that could render a similar outcome.

c. Presentation of event to Operations Curriculum Review Committee for inclusion into the Training program.

COMMITMENTS

No commitments are made in this LER.